Signaling system and electron-tube circuits



Oct. 15, 1929. P. emouo 1,732,044

SIGNALING SYSTEM AND ELECTRON TUBE CIRGUI TS Filedsept. 11, 1924,

i I P/EPPE G/IPOUD 5 INVENTOR TTORNEY Patented Oct. 15 1929 UNITED STATES PIERRE GIRO'UID, OF PARIS, FRANCE SIGNALING SYSTEM AND ELECTRON-TUBE CIRCUITS Application filed September 11, 1924, Serial No. 737,030, and in 'France October 15, 1923.

My invention relates to electron tubes of the double grid type and to systems in which said tubes are incorporated. My invention also re lates to methods of amplification and detec- 5 tion.

One of the principal objects of my invention is the provision of a double grid element tube which has a low manufacturing cost, large electron emmission and which requires a source of power of comparatively low potential for supplying the desired anode current.

Another object of my invention is the provision of electrical systems in which my improved double grid electron tubes are incorporated.

Other objects and advantages of my invention will be evident from the following description taken in connection with the accompanying drawings in which;

Figs. 1 and 1A are combined structural and diagrammatic representations of a preferred embodiment of my double grid electron tube.

Figs. 2 and 3 are schematic diagrams of preferred systems in which my electron tubes are incorporated.

Referring to Figures 1 and 1A, my double grid electron tube comprises an evacuated envelopor enclosure 1, a central horizontal wire or cathode 4 of circular cross-section surrounded by an inner horizontal cylindrical grid element 2 appropriately spaced therefrom. The grid element 2 in turn is sur rounded by a second horizontal cylindrical grid element 3 suitably spaced therefrom. A horizontal cylindrical plate element 2 surrounds the outer grid 3 and is suitably spaced therefrom. The cathode 4: is centrally positioned and the remaining electrodes are concentrically mounted with respect thereto.

The diameters of the cylindrical grid elements may be the same. In this case both of them may be wound in the form of a helix of the same diameter and pitch, the turns of one occupying thespaces between the turns of the other and vice-versa.

The ends of the inner grid element 2 are secured to spacing rods 13 and 14 which are in turn joined together by rod 12 as shown in Fig. 1A. The horizontal rod 12 is suitably secured to the vertical supporting rod 5 which is embedded in the glass post 6 in which are also welded the rods for supporting the other elements of the tube.

The rods for supporting the various elements of the tube terminate in exterior metallic plugs 7, 8, 9, 10 and 11 for making appropriate external connections for the various elements of the tube.

In a double grid electron tube the space charge may be substantially neutralized by applying a positive potential to one of the grid elements. This will accentuate the electected or amplified or both. The plate-filament circuit comprises the source of power 11, and an oscillation responsive device 15, all connected in series as shown. The inner grid element 2 may have a suitable positive potential 'bias imparted to it by connection to the X terminal of the source of power 11 shown, or by connection to any one of a suitable number of taps connected to the source of power 11.

A plurality of my double grid electron tubes may be connected in cascade or-one or more of my double grid electron tubes may be connected in cascade with various different types of tubes to form an amplifying system.

Referring to Fig. 3 my electron tube 1" comprises a filament or cathode 4, an outer grid element 3, an inner grid element 2 and a plate or anode 2' The cathode or filament 4 may be suitably heated from a source of power 10, the value source of power 11 for supplying the anode current as shown. The inner grid element 2 is connected to the terminal of the source of power 11 through coil 20 and an oscillation responsive device 21,-both connected in series with each other as shown. The coil 20 is inductively coupled to either the primary winding or the secondary winding of inductive coupling device 17 for effecting regeneration vto thereby regulate the degree of amplification and for causing the tube to function as an oscillation generator for autodyne reception, amplification, and detection of'oscillations if so desired.

A plurality of my double grid electron tubes may be connected in cascade or one or more of these tubes may be connected in cascade with'one ormore other tubes of the same vor different types in amplifying sys- J tems.

I as

While, I have shown and described various preferred embodiments of my invention I do not limit myself to the same but may employ such other modifications as come within the spirit and scope of my invention;

I claim: V 4 1. The combination with an electron discharge device having a cathode, an anode,

and a pair of control electrodes interposed therebetween, of an mput clrcuit connected between the cathode and one of the control I electrodes, an anode circuit including a source of potential connected'between cathode and anode, and a circuit including asound responsive deviceconnected between the second control electrode and the positive terminal ,ofthe source of anode potential, said last mentioned circuit being in inductive relation with the input circuit-"i r 2.- The combination with an electron discharge device having a cathode, an anode, an innergrid and'an outer grid, saidgrid electrodes 'being interposed between cathode and anode, of a tuned input circuit connectedtbetween the cathode and the outer-grid, a circuit including a source of potential connected between cathode and anode, and an output circuit connected between the outer grid an'd the positive terminalzof the'source .of anodepotential,saidontpnt ci-rcuitincluding a sound responsive device and an inductance variably coupled to the tuned input circuit for producing self-oscillation where by reception on the autodyne principle is effected.

PIERRE GIROUD. 

